Com Pi - Legacy Product

Created 24/11/2016 | Com Pi for the Raspberry Pi

Control the Raspberry Pi over RS232 or connect to external serial accessories.

1-Wire® to I2C host interface with ESD protection diode.

Stackable with other Raspberry Pi accessory boards.

Buffered 5V I2C port.

External 5V power input for 1-Wire® interface.

The Com Pi from AB Electronics is a communication add-on board for the Raspberry Pi supporting RS232 and 1-Wire® protocols. A 5V buffered I2C port is also provided on the board.

The Com Pi is pin compatible with the the Raspberry Pi model B+.

The RS232 port is connected to the UART port on the Raspberry Pi using a MAX3232 interface. The MAX3232 IC converts the 3.3V UART port to RS232 voltages allowing communication with RS232 compatible devices over a DB9 serial cable or with the use of a null-modem cable the board allows terminal access with linux on the Raspberry Pi using a terminal application. The RS232 port can be accessed through the DB9 port or the solder points on the PCB.

The 1-Wire® port is based around a DS2482-100 I2C to 1-Wire® bridge device. The DS2482-100 provides bi-directional protocol conversion between the I2C port on the Raspberry Pi and any attached 1-Wire® slave devices. An ESD Protection Diode is used to protect the Com Pi and Raspberry Pi from electrostatic spikes on the 1-Wire® port. Connections to the 1-Wire® port can be made through the RJ-12 socket or the solder points on the PCB. Wiring diagrams for the RS232 and 1-Wire® ports can be found on the Com Pi datasheet.

A 5V input port is also provided allowing you to use an external power supply on the 1-Wire® interface, reducing the load on the Raspberry Pi. If you choose to use the external 5V input please remove the jumper on the board to isolate the Raspberry Pi 5V bus.